r-PET/POE/EAA共混材料性能的研究

以回收聚对苯二甲酸乙二醇(酯r-PET)为基体材料,乙烯-辛烯共聚(物POE)为增韧材料,乙烯-丙烯酸共聚物(EAA)为相容剂,制备了r-PET/POE/EAA共混材料。用DSC、SEM分析了POE及EAA对r-PET结晶性能、断面结构的影响,并测试了共混材料的力学性能。结果表明:加入12%POE后,r-PET/POE共混材料的熔融温度降低了1.76℃,结晶度降低了16.49%,断裂伸长率及缺口冲击强度明显提高,弯曲强度和拉伸强度略有下降;在r-PET/POE共混材料中加入1.5%EAA后,POE球状粒子嵌入r-PET基体中,二者相容性提高,结晶速率加快;与纯r-PET相比,r-PET/POE/EAA共混材料的断裂伸长率和缺口冲击强度分别提高了698.01%和227.45%柔,韧性也大幅度提高。     

PP/OBC共混材料的性能

以均聚聚丙烯(PP)为原料,乙烯-辛烯嵌段共聚物(OBC)为增韧材料,采用双螺杆挤出和注塑成型方法制备PP/OBC共混材料,用SEM、DSC分析OBC对PP断面相结构和结晶性能的影响,测试共混材料的力学性能.结果表明:OBC在PP基体中分散较均匀,形成了以PP为连续相,OBC为分散相的“海-岛”结构;合20％OBC的PP/OBC共混材料,与纯PP材料相比,熔融峰温度和熔点分别下降了4.47和4.81℃,熔融结晶温度上升2.3℃,缺口冲击强度和断裂伸长率分别提高了142.43％和2.77倍,柔韧性大幅度提高.     

POE熔融接枝GMA的制备及其与PBT共混增韧

在双螺杆挤出机上采用熔融接枝法制备了POE-g-GMA和POE-g-(GMA-co-St),考察了POE、POE-g-GMA和POE-g-(GMA-co-St)对聚对苯二甲酸丁二醇酯(PBT)的增韧作用.结果表明POE和单组分接枝的POE-g-GMA对PBT的缺口冲击韧性的改善作用都不大;而双组分接枝的POE-g-(GMA-co-St)对PBT具有显著的增韧作用.当弹性体POE-g-(GMA-co-St)用量为15%时,共混物的缺口冲击强度为45.84 kJ/m2,是缺口冲击强度为1.28 kJ/m2的纯PBT的35倍多.SEM显示,PBT/POE-g-(GMA-co-St)共混体系中分散相比PBT/POE-g-GMA共混体系的分散相具有更好的分散性.同时对比了几种外来增韧剂对PBT性能的影响.     

芳酰胺类化合物对PP/OBC共混材料性能影响

以均聚聚丙烯(PP)为原料,乙烯-辛烯嵌段共聚物(OBC)为增韧材料,芳酰胺类化合物(TMB-5)为成核剂,采用双螺杆挤出和注塑成型方法制备PP/OBC共混材料,用DSC、WAXD和POM分析了TMB-5对PP/OBC共混材料结晶性能、晶型和晶体形态的影响,并测试了共混材料的力学性能。结果表明:随着OBC含量的增加,PP/OBC共混材料缺口冲击强度和断裂伸长率明显增大,拉伸强度和弯曲强度有所下降;含1.0%TMB-5母粒、15%OBC的PP/OBC共混材料,于152℃附近出现β晶型的特征熔融峰,熔融结晶温度比纯PP提高了11.68℃,β晶型相对含量为52.74%,PP球晶尺寸减小,缺口冲击强度和断裂伸长率分别提高了236.46%和256.01%,柔韧性大幅度提高。     

双单体AA/St熔融接枝OBC的研究

利用HAAKE转矩流变仪,采用熔融接枝法制备了双单体丙烯酸/苯乙烯接枝乙烯-辛烯嵌段共聚物(OBC-g-(AA-co-St)),探讨了丙烯酸(AA)、苯乙烯(St)和过氧化二异丙苯(DCP)的用量对接枝反应的影响,并通过红外光谱分析表征了该接枝产物的结构。结果表明:采用熔融接枝技术,成功地将AA接枝到OBC上,得到了OBC-g-AA接枝共聚物;当AA为4%、DCP为0.2%、反应温度为170℃、反应时间为12 min时,OBC-g-AA的相对接枝率达到峰值;另外,第二单体St的引入使接枝率有所提高,当St与AA质量比为1:2时,其相对接枝率达到1.68。     

PBT与官能化POE共混过程中的增容反应研究

采用带流变槽的HAAKE流变仪研究了乙烯-辛烯共聚物（POE）和甲基丙烯酸缩水甘油酯接枝乙烯-辛烯共聚物（POE-g-GMA）与聚对苯二甲酸丁二醇酯（PBT）共混物的黏度随共混时间的变化过程，并对这两种共混物的断面形貌和力学性能进行对比分析。结果表明，由于POE-g-GMA能够与PBT发生原位增容反应，使得POE-g-GMA颗粒的粒径小、分散均匀，体系黏度随共混时间先长时间持续上升，然后保持不变，体系最终黏度也随着POE-g-GMA浓度升高而升高；然而在不发生反应的PBT／POE体系中，POE颗粒分散性差，颗粒粒径大，体系黏度受POE的浓度影响相对较小且随时间基本上保持不变。由于POE-g-GMA与PBT之间的增容反应使得PBT／POE-GMA的力学性能优于PBT／POE，并且冲击强度随POE-g-GMA浓度呈现两个阶段变化，即低于临界浓度时冲击强度缓慢升高，高于临界浓度时冲击强度快速升高。     

PA6/PBT合金的制备与性能

将乙烯–辛烯共聚物接枝马来酸酐(POE-g-MAH)和乙烯–辛烯共聚物接枝甲基丙烯酸缩水甘油酯(POEg-GMA)复配作为增容剂,采用熔融共混的方法制备尼龙(PA)6/聚对苯二甲酸丁二酯(PBT)合金。通过扫描电子显微镜、力学性能和吸湿性研究了PA6/PBT配比和增容剂用量对合金性能的影响。研究表明,增容剂的加入能改善PA6/PBT合金的相容性,PBT和增容剂的加入能有效地抑制PA6的吸水率。添加15份增容剂可使合金的缺口冲击强度达到15.5 k J/m~2,相比未加入增容剂提高385.9%。     

反应挤出法制备POE-g-(GMA-co-St)的研究

以甲基丙烯酸缩水甘油酯（GMA）为接枝单体,苯乙烯（St）为接枝共单体,在双螺杆挤出机上对乙烯-辛烯共聚物（POE）进行熔融接枝,制备了POE—g-（GMA—co—St）。研究了引发剂用量、单体用量、共单体用量和抑交联剂亚磷酸三苯酯等对POE接枝物接枝率和熔体流动速率的影响,利用红外光谱对接枝物进行了表征。研究袭明,St的加入能有效提高GMA的接枝率,亚磷酸三苯酯有效抑制了POE的交联。最佳配方为：过氧化二异丙苯（DCP）为0．15份,GMA为3份,St为3份,亚磷酸三苯酯为1份。     

PET/POE共混物增韧改性研究

采用三经甲基丙烷三丙烯酸醋(TMPTA)作为强化交联剂,加人聚对苯二甲酸乙二醇醋(PET)/乙烯一辛烯共聚物(POE)体系中进行共混辐照并观察共混物性能上的变化。利用悬臂梁冲击试验机、扫描电子显微镜等对共混物进行了性能测试及结构表征。结果表明,当TMPTA含量为1%(质量分数,下同)时,共混物的冲击性能达到了纯PET的3倍;当TMPTA含量为3%时,其冲击强度能达到纯PET的2. 5倍。与纯PET相比,共混物的冲击性能有了较大幅度的提高。     

PP/OBC/EPDM-g-MAH复合材料的制备及性能

以聚丙烯(PP)为基体材料,乙烯-辛烯嵌段共聚物(OBC)为增韧材料,三元乙丙橡胶接枝马来酸酐共聚物(EPDM-g-MAH)为相容剂,制备了PP/OBC/EPDM-g-MAH复合材料。用DSC、SEM、转矩流变仪分析了OBC及EPDM-g-MAH对PP结晶性能、断面相结构、流变性能的影响,测试了复合材料的力学性能。结果表明:加入15%OBC,PP/OBC复合材料的熔融温度升高了1.63℃,结晶度降低了5.4%,断裂伸长率及缺口冲击强度明显提高,弯曲强度和拉伸强度有所下降;含4%EPDM-g-MAH的PP/OBC/EPDM-g-MAH复合材料,OBC粒子均匀分散在PP基体中,粒径明显细化,熔融塑化扭矩值降低,结晶速率加快;与纯PP相比,断裂伸长率和缺口冲击强度分别提高了128.57%和107.96%,柔韧性有较大幅度提高。     

HDPE/r-PET原位微纤物微观形态与力学性能

以高密度聚乙烯(HDPE)和回收聚对苯二甲酸乙二醇酯(r-PET)为原料,通过反应挤出、冷拉伸、退火工艺制备了HDPE/r-PET原位微纤物。研究了扫描电镜(SEM)的制样方法即用液氮冷冻、脆断样品、聚四氟乙烯带包覆、在沸腾的二甲苯中刻蚀7～10min和不同r-PET用量、不同拉伸比制备出的系列HDPE/r-PET原位微纤物的力学性能。结果表明,通过SEM可清晰地看到形成的微纤,原位微纤物的拉伸强度和冲击强度都随拉伸比的增大而增大;r-PET质量分数为15%时,原位微纤物的拉伸强度和无缺口冲击强度达到最大值;HDPE/r-PET原位微纤物的适宜注塑温度为210℃。     

PP/POE共混物力学性能研究

用双螺杆挤出机制备了聚丙(烯PP)/聚烯烃弹性(体POE)共混物,研究了POE用量对PP/POE共混物冲击性能、拉伸性能及弯曲性能的影响。结果表明:随着POE含量的增加,PP/POE共混物的冲击强度明显提高;拉伸强度及拉伸模量弯、曲强度及弯曲模量、断裂伸长率及断裂强度均减小。     

Mechanical Properties and Morphology of UHMWPE/PC/HDPE-g-MAH Blends

The blends of ultrahigh molecular weight polyethylene (UHMWPE), polycarbonate (PC) compatibilized by using a high-density polyethylene (HDPE) grafted with maleic anhydride (MAH), HDPE-g-MAH, were processed by melt extrusion. Two grafting degree of HDPE-g-MAH, 0.5% and 1.2%, were separately prepared by melt-graft and solution-graft methods. The grafting degree of HDPE-g-MAH shows a significant role in enhancing tensile strength of the blends. The compatibilization mechanism of HDPE-g-MAH in the blends analyzed by FTIR indicates that a new grafting product, HDPE-g-PC, was in situ formed. The improvement of phase interface between UHMWPE and PC by addition of HDPE-g-MAH was observed by SEM.     

聚氨酯／顺丁橡胶共混物结构与性能的研究

采用物理共混的方法,制备了廉价的ＢＲ和贵的热塑性聚氨酯（ＴＰＵ）共混物。利用电子拉力机,液变仪,动态粘弹仪,偏光显微镜和电子显微镜对力学性能、流变性能,动态粘弹性和形态结构进行了研究和分析。结果表明,ＢＲ和ＴＰＵ有较好的相容性,ＴＰＵ／ＢＲ共混物能达到使用要求,一些性能好于纯ＴＰＵ《     

Barrier Properties of Blends Based on Liquid Crystalline Polymers and Poly(ethylene terephthalate)

Abstract

Blends of poly(ethylene terephthalate) (PETP) and two different thermotropic liquid crystalline (LC) polymers of the Vectra-type were prepared by melt mixing. Oxygen and water vapor permeability, light transmission and welding properties were measured on compression-molded and film-blown specimens. SEM showed that the LC polymers were the disperse phase with a good phase adhesion to the PETP matrix in the majority of the compression-molded blends. The 50/50 blend based on the low melting point LC polymer showed possibly a continuous LC polymer phase. The film-blown specimens showed LC polymer spheres at low LC polymer content. Above a certain LC polymer content (10-30% LC polymer), fibrous and ellipsoidal LC polymer particles was the dominant morphological feature of the blends. Density measurements showed that the void content in the blends was low. The compression-molded blends based on the high melting point LC polymer showed permeabilities conforming to the Maxwell equation assuming low permeability (LC polymer) spheres in a high permeability (PETP) matrix. The compression-molded blends based on the low melting point Vectra showed lower permeabilities than predicted by the Maxwell equation, particularly at high LC polymer content. The film-blown blends showed extensive scattering in the permeability data. The blend with 30% low melting LC polymer exhibited a 96% lower oxygen permeability than PETP. This was due to a reduction in both oxygen diffusivity and solubility. Ellipsoidal and fibrous LC polymer particles increased the diffusional path and lowered the diffusivity. The transparency of the compression-molded samples was lost already at 1% LCP. The blends showed welding properties superior to those of PETP.     

Preparation and Properties of PB-1/PP Blends

Crystallization behavior, dynamic mechanical properties, mechanical properties and rheological properties of isotactic polybutene-1/polypropylene (PB-1/PP) blends prepared by melt-blending the two components through Brabender extruder were mainly studied via POM, DSC, DMA, capillary rheometer and so on, respectively. The results indicated that after adding PP in PB-1: size of the spherical crystal and degree of crystallization of PB-1 in the blends decreased, its melt temperature and crystallization temperature unchanged; tensile property of the blends was decreased, but impact and flexural properties were improved; change of the melt viscosity of the blends with the shear rate was more sensitive than pure PB-1.     

PU/PVC共混超滤膜的制备及性能

采用湿法相转化制膜技术制备PU/PVC共混膜、PU/PVC/SiO2共混膜。PVC可以改变铸膜液体系在凝固浴中的分相速度,提高成膜性及改善膜的微孔结构,在此共混物中加入SiO2可以显著改善膜的微孔结构,并提高PU共混膜的水通量,可用于超滤。用扫描电镜对膜的结构形态进行了观察。     

Study on the Crystallization Kinetic and Characterization of Poly(lactic acid) and Poly(vinyl alcohol) Blends

In this study, poly(lactic acid) (PLA) and poly(vinyl alcohol) (PVA) blends, with PLA/PVA mass ratios of 100/0, 90/10, 80/20, 70/30, 60/40, 50/50, and 40/60, were prepared by means of the melt blending method. The result of torque measurements and thermal gravimtric analysis tests showed that the addition of PLA can decrease the melt viscosity of PVA and that the second degradation step of PVA nearly disappeared for the PLA₈₀/PVA₂₀ blend. The absorbance peaks of the carbonyl group and the hydroxyl group in the Fourier transform infrared spectra of PLA/PVA blends had significant shifts to lower wave numbers, indicating that there were interactions between these two groups. Combined with the result of the differential scanning calorimetry curves, this interaction would be favorable for improving miscibility. The X-ray diffraction patterns and the polarized light microscope (PLM) micrographs showed that PVA can serve as a nucleating agent to promote the crystallization of PLA in PLA/PVA blends. Moreover, the PLA₈₀/PVA₂₀ blend gave the highest growth rate of PLA spherulite.